Lithium battery
Lithium batteries are primary batteries that have lithium as an anode, these types of batteries is called lithium-metal batteries. They stand apart from other batteries that have high charge density (long life) and high cost per unit. Depending on the design and chemical compounds used, lithium cells can provide voltages from 1.5 V (comparable to the zinc-carbon or alkaline battery) to the 3.7 V. Disposable primary lithium batteries must be distinguished from the secondary forms of lithium-ion or lithium-polymer, which are rechargeable batteries. Lithium is especially useful, because its ions can be arranged to move between the anode and cathode, using the intercalated lithium compound as the cathode material but without using the lithium metal as the anode material. Pure lithium will instantly react with water, or even moisture with the air, the lithium in lithium-ion batteries is in a less reactive compound. Mistreatment during charging or discharging can cause some out outgassing of the contents, which will result in explosions or fires. Lithium batteries are widely used in portable consumer electronic devices, and in electric vehicles ranging from full sized vehicles to radio controlled toys. Lithium batteries find application in many long-life, critical devices, such as pacemakers and other implantable electronic medical devices. These devices use specialized lithium-iodide batteries designed to last 15 or more years. But for other, less critical applications such as in toys, the lithium battery may actually outlast the device. In such cases, the expensive lithium battery may not be cost effective. Lithium batteries can be used in place of ordinary alkaline cells in many devices, such as clocks and cameras. Although they are more costly, lithium cells will provide much longer life, thereby minimizing battery replacement. However, attention must be given to the higher voltage developed by the lithium cells before using them as a drop-in replacement in devices that normally use ordinary zinc cells. Small lithium batteries can be found in small, personal electronic devices such as calculators, PDAs, digital cameras, thermostats, watches and remote car locks. The computer industry's drive to increase battery capacity can test the limits of sensitive components such as the membrane separator, a polyethylene or polypropylene film that is only 20-25 µm thick. The energy density of lithium batteries has more than doubled since they were introduced in 1991. When the battery is made to contain more material, the separator can undergo stress. Lithium batteries can provide extremely high currents and can discharge very rapidly when short circuited. Although this is useful where high currents are required, a rapid discharge of lithium battery can result in the overheating of battery, rupture, and even an explosion. Lithium-thionyol chloride batteries are particularly susceptible to this type of discharge. Consumer batteries usually incorporate overcurrent or thermal protection or vents to prevent an explosion. Power banks Power banks are popular for charging smartphones and mobile tablet devices. A powerbank is a portable device that can supply power from the built-in batteries through a USB port. They generally recharge from the USB power supply. Technically, a powerbank consists of the rechargeable Lithium-Ion or Lithium batteries that has been installed in protective casing, guided by the printed circuit board (PCB) which provides various protective and safety measures. Timothy Mok had bought the power bank from Daniel Mok for Christmas present in January 2014 (which is a Chronovoski box), which earlier it had been announced and mentioned the battery pack in 23 November 2012 while at Funan DigitaLife Mall, and we decided to have one when the schools have expanded the usage respectively. Betsy Koh had later bought Xiaomi box. Previously, we had went to A.C. Ryan office at Kaki Bukit to buy portable chargers. The specifications are: *Capacity in Wh: Total power capacity measured by multiplying mAh by voltage. *Capacity in mAh: mAh stands for milli-Ampere hour and measures the amount of power flow that can be supplied by a certain power bank at a specific voltage. Many of the manufacturers rate their products by 3.7 V, the voltage of cells inside. Since USB outputs at 5 V, calculations at this voltage will yield the lower mAh number. For example, a battery pack that is advertised with 3000 mAh capacity (at 3 V) will produce 2220 mAh at 5 V. Power losses due to efficiency of charging circuitry will occur. *Simultaneous charging and discharging: need to specify if the powerbank can be used while charging. *Number of output USB ports: This specifies the number of devices that can be charged simultaneously. *Output current rating: This specifies that the current rating if can charge at the maximum. The higher the better, the bigger the powerbank. This can vary from output port to output port. *Input current rating: This specifies that the amount of current from the power bank is able to draw at the maximum level while it is charged. *Safety Protections: The Over Voltage Protection, Over Charging Protection, Over Current Protection, Over Heat Protection, Short Circuit Protection and Over Discharge Protection are common safety measures observed with the standard power banks. *LED Indications: The LED glows as per indicating the amount of charging left in the power bank. Compatibility Although a standard exists for USB chargers, there are two areas of common incompatibility: *The connector on the device needs to be charged. There are several current and many obsolete connectors including: **The Micro-USB connector **The Mini-USB connector **The USB-C connector **The Lightning connector **The J10 connector **Various sizes of coaxial power connector, particularly the smaller sizes **The 3.5mm jack and the 2.5mm jack It is essential that the connectors on the device and the charger match quickly so that the correct polarity is used. Reversing the polarity between the battery and the charger is likely to cause battery failure and even charger failure. The failures can lead to fire or damaged / destroyed equipment. *The charging port. This may be smart and dumb, and even in various current ratings. Compatibility varies and must be checked to maximize safety. A mismatched charger will charge more slowly and sometimes not at all. Restrictions On 16 May 2012, the United States Postal Service (USPS) banned shipping of lithium battery to the overseas address after fires from the transport of batteries. This restriction make it difficult to send anything containing lithium batteries to military personnel overseas, as the USPS was the only one shipment into the addresses, the ban was lifted on 15 November 2012. Although devices containing lithium and lithium-ion batteries can still be placed in checked-in luggage, spares and power banks must be placed in hand-carry luggage. They must be protected against short circuiting and example tips are provided in the transport regulations on safe packaging and carriage, e.g. such batteries should be in the original protective packaging, or "by taping over the exposed terminals or placing each battery in a separate plastic bag or protective pouch". The maximum size of each battery (whether installed in a device or as spare batteries) that can be carried is one that has an equivalent lithium content (ELC) not exceeding 8 grammes per battery. Except, that if only one or two batteries are carried, each may have an ELC of not more than 25 grammes each. The ELC for any battery is found by multiplying the ampere-hour capacity of each cell by 0.3 and then multiplying the result by the number of cells in the battery. The resultant calculated lithium content is not the actual lithium content but a theoretical content solely for transportation purposes. When shipping lithium-ion batteries however, if the total lithium-ion content in the cell exceeds 1.5 g, the package must be marked as "Class 9 miscellaneous hazardous material". From 1 January 2013, much stricter restrictions are imposed by IATA regarding the carriage of lithium batteries by air. They were adopted by the International Postal Union, however, some countries such as the UK, will not accept lithium batteries unless they are included in the equipment they power. Because of the above risk, shipping and carriage of the lithium batteries are restricted in such situations, particularly those travelling with lithium batteries on the air. The United States Transport Security Administration since 1 January 2008, announced restrictions on lithium batteries in checked and hand-carry luggage. The rules forbid lithium batteries that are not installed in the checked-in luggage and restrict them on carry-on luggage by total lithium content. Australia Post also prohibited the transport of lithium batteries in 2010. UK regulations for transport are under National Chemical Emergency Centre in 2009.